Fluid compressor



1927' F. B. STEARN s FLUID COMPRESSO R Filed May 24 1924 3 Sheets-Sheet l INVENTOR BY QW L m.

ATTORNEYS Aug. 9, 1927. ,418

F. B. STEARNS FLUID COMPRESSOR Filed May 24. 1924 v sheets-sheet 54 lNVENTOR E BY WSW um ATTORN EYS Patented Aug. 9, 1927.

UNITED STATES PATENT 1 OFFICE.

FLUID COMPRESSOR.

Application filed May 24:, 1924. Serial No. 715,538.

This invention relates to fluid compressors. The primary requisites in obtaining the best mechanical and volumetric efiiciency of ports for the compression chamber which are of an area capable of handling a volume of fluid equal-to the capacity of the compression chamber, and to provide valve mechanism for controlling the ports which will oplu erate proportionately to the speed at which the compressor element operates. It therefore follows that the area of the ports in large volume compressors are larger than in small volume compressors, and that the valve 1 mechanism operates more rapidly in high speed compressors than in low speed compressors. So far as I am now aware, prior compressors are incapable of efliciently handling a large volume of fluid at high speed, 0 for various reasons, among which are the necessity of employing large valves of such type and so operated that they will not withstand the rapid movement at which they must oe operated without quickly becoming distorted or broken.

There are many instances where a compressor having a large volume and high speed can be used, and for illustratioml have shown and described such a compressor used :0 with a self igniting engine for supplying compressed air to the engine cylinder for scavenging after explosion and also supplying precompressed air thereto.

An object of my invention is to provide a compressor which will supply a. large volume of compressed fluid at high speed.

Another object of my invention is to provide valve mechanism which can be operated at a high speed to control the passage of air 49 to and from a compressor of large volume, so that the greatest possible mechanical and volumetric efficiency will be obtained.

Another object of my invention is to provide a compressor in which the compression chamber is substantially completely emptied of compressed fluid after each compression operation.-. Another ob ect of my invention 1s to provide asingle valveelem'ent for a compressor which controls the admission of fip d int!) the compression chamber, and which also controls the passage of compressed fluid from the compressor chamber. compressors is to provide inlet and outlet- These andother objects and the invention itself will be more clearly understood from the following detailed description.

In the accompanying drawings Fig. 1 is a top plan view of a compressor embodying my invention connected-with a self-igniting engine of the solid fuel injectron type;

Fig. 2 is a medial vertical section of the same taken on line 2-2 of Fig. 1;

Fig. 3 is a section through the compressor taken on line 3-3 of Fig. 2;

Fig. 4 is a top plan view of the valve sleeve spider;

Fig, 5 is a top plan view of the stationary valve element removed from the cylinder head;

Fig. 6. is a top plan view of the'movable vided with bearings 11 in which a crank shaft 12 is rotatably mounted. The end of the crank shaft extends through one end of the casing and a fly wheel 13 is secured thereto. An engine cylinder 14 is secured upon the casing, and a piston 15 is adapted to reciprocate within the cylinder, the piston being connected to the crank shaft by a piston rod 16. A pair of oppositely disposed exhaust ports 17 are provided in the cylinder wall located so that they will be covered and uncovered during each reciprocating movement of the piston.

A cylinder head 18 is secured to the upper end of the cylinder, and a fuel injecting device 19 is mounted in a central aperture extending through the head. This device can be of any conventional construction for in termittently supplying a charge of fuel, such as oil, into the explosion chamber which is formed by the top of the cylinder and the cylinder head. A pair of pipes 21 extend from the air compressor and are'securedin open communication with conduits 22 extending through opposite sides of the cylinder head. The conduits terminate in passages diverging outwardly from the inner wall of the cylinder head and on opposite sides thereof. Valves 23 are adapted to be seated against the inner head wall to open and close the passages therein, and the stems 24 are slidably mounted in bearings 25 secured through the cylinder head. A, coil spring 26 surrounds each of the stems and bears against the engine head, being secured against removal by collars 27 secured to the stem. Rocker arms 28 are secured to shafts 75 which are rotatably mounted in bearing brackets 29 secured upen the head, and. rods 76 are reciprocated by the cam shaft 30, and are connected to arms 77 secured to the shafts 7 6.

The arms 28 are positioned to engage th upper end of the valve stems and are operated to intermittently move the stems in wardly, thereby unseating the valves to admit compressed air from the pipes 21 into the explosion chamber of the engine. The

springs normally tend to maintain the valves in position so that they close the outlet end of the passages within the head.

A compressor cylinder 31 is secured upon the top of the crank case in open communication with the interior thereof and adjacent the engine cylinder, and a piston 32 having an annular reduced end portion is mounted to reciprocate therein. A pin 33 is carried by the piston, and a rod 34 is connected to such pin and the'crankshaft 12. The cylinder is-provided with a plurality of spaced air inlet ports 35 arrangedin the same flange around the upper end thereof,

and outlet ports 36 are provided in the cylinder wall intermediate the inlet ports and the-end of the cylinder. The pipes'21 are secured'to the compressor cylinder and provided passages for conducting the compressed air from ,the outlet ports to the enginehead.

The compressor cylinder is provided with a closure head 37 which is secured upon the upper end thereof by bolts 38, and an apertured hub 39 extends centrally therefrom into the cylinder. The inner endof the hub terminates in an interiorly-extending flange 40 formed to provide a bearing through which a stem 41 is slidably-mounted. A hollow packing nut 42 is threaded into the upper end of the apertured hubportion of the head, and provides a bearing for the stem 41 which extends therethrough. Astationary hdllow valve element is mounted within the upper end of the compressor cylinder an'd is positioned in opposedrelation to the reciprocating piston 32..JThe stationary valve element consists of an annular head 43 of smaller diameter than the cylinder, havlng a skirt portion, 44 extending slots 58 will tending flange 45 of an outside diameter substantially that of the bore of the cylinder. The flanged portion of the skirt is secured against the cylinder head by screws 46. The skirt 44 of the stationary valve element, including the flanged end, is provided with preferably equally spaced slots 47 which extend lengthwise thereof and terminate adjacent the cylinder head portion. An expanding annular ring 48 is mounted in an annular groove in the side wall of the skirt, below the ends of the slots. The inner end of the stem is threaded, and a valve supporting plate, a spider 50, is screwed thereon. This plate is pro vided with a central internally" threaded hollow hub portion 51, and also with arms .52 which extend radially from the periphery thereof. The arms are arranged so that they will extend through the slots in the skirt portion of the valve element and are provided adjacent their outer ends with bolt holes 53. A slidable cylindrical valve ele-' is provided with a plurality of slots 58 which a extend lengthwise thereof and terminate adjacent the lower end of the skirt.

The valve element 54 which is secured to the arbor is of such thickness that it will engage the skirt 44 of the stationary valve element and the inner wall cf the cylinder.

The valve element 54 is vertically reciprocated by the movement of the stem 41 to which the spider is secured. The arrange-.

ment of the movable valve element is such that it will coverthe air inlet ports in the cylinder wallwhen in its lower position, and when in such osition the lower ends, of the stationary valve element, thereby establishllO 'e beneath the head of the ing communication between the compression chamber beneath the head of the'stationary valve element, and the outlet ports 36, Up-

ward movement of the movable 'valve element first covers the slots 58 beneath the skirt of the stationary valve element and then uncovers the inlet ports35. The slots 47 through which the spider .ajrmsextend,

permit the spider to be reciprocated a'limite'd distance, thereby reciprocating-the movable valve, element between the cyhnder wall and the skirt beneath the cylinder head. The

expanding-rings 56vand 48 will engage r i spectively the cylinder walland the inner wa l of t e ovable valve member thereby" providing a sealing which materially increases the compression of air within the compression chamber and prevents leakage from the conduits into compression chamber.

The cam shaft is secured in bearing 61 and is positioned above the crankshaft, and a gear 62 is secured to the cam shaft, being driven by a chain from a gear 63 secured to the crank shaft. A plate 64 is secured to the end of the gear 62 and an ecccntrically arranged shaft 65 projects therefrom. A rocker arm 66 is pivotally connected to the outer end of the stem 41 and is secured to one end of a shaft 67 which is mounted in a bearing 68 secured to cylinder head. A rocker arm 69 is secured to the other end of the shaft 67 and is pivotally connected to one end of a rod 70. The other end of the rod 70 terminates in a bearing 71 which is loosely secured upon the eccentrically extending shaft 65. The rotation of the crankshaft causes the eccentric shaftto be rotated with the gear 62. thereby reciprocating the rod 70 and rocking the shaft 67 which reciprocates the stem 41.

The compression chamber is formed within the cylinder. intern'iediate the head of the stationary valve element and the movable piston. The reduced end of the piston will project within the annular movable valve element, when approaching its extreme upward travel and will extend in close proximity to the head of the stationary valve element when in its extreme upper position, thereby displacing substantially the entire volume of compressed fluid from the compression chamber.

The mechanisms for operating the movable compressor piston and the movable valve element are so arranged, and operated, that as the compressor piston starts down the inlet ports are uncovered by the mova-v ble annular valve element, and they remain uncovered until the compression piston is at the bottom of its travel. A fresh sup ply of air passes into the compression chamber through the ports when uncovered. As the compressor piston starts its upward travel, the inlet ports will be closed by the annular valve element and as the annular valve element moves down the slots in the inner wall thereof will extend below the head of the stationary valve element, permitting the compressed air to pass through pass therebetween except when one of the valve elements is moved to provide a passage, and the movable valve element is associated with the inner wall of the cylinder so that compressed air can not pass therebetween. The movable valve element and the stationary valve element construction which I have provided will operate at high speeds while air is compressed in large volume without becoming distorted or broken, thereby supplying air under compression necessary for completely scavenging and supercharging self igniting types of engine to produce the power necessary for commercial use.

Various changes can be made in the construction described without departing from the spirit of my invention and the scope of the claims.

\Vhat I claim is 1. In a fluid compressor, a cylinder having inlet ports therein, a piston reciprocable in said cylinder, a stationary valve element within said cylinder, and a reciprocable cylindrical valve element intermediate said stationary element and the inner wall of said cylinder, said reciprocable element controlling the passage of fluid through the inlet ports in said cylinder and cooperating with said stationary elementto provide out-- let ports for the passage of compressed fluid.

2. In a fluid compressor, a cylinder having inlet and outlet ports, a piston reciproca ble in said cylinder, a stationary skirted valve element extending within said cylinder, said member having axially extending slots in its skirt portion, a reciprocable stem extending within said cylinder, a spider se cured to said stem within said cylinder, said spider having radial arms extending through the slots in said valve skirt. and an annular valve element secured tothe arms of said spider, said valve elementsealing the space intermediate said stationary valve element and said cylinder and controlling the passage of fluid compressed within said cylinder intermediate said piston and valve elements.

3. In a fluid compressor, a cylinder having inlet and outlet ports, a head secured to said cylinder, a piston reciprocable in said cylinder, a hollow valve element. an axially slotted skirt portion for the valve element secured to said head, an annular reciprocable valve element intermediate said stationary element and said cylinder and arranged in leak-proof contact therewith, a spider having arms extending through the slots in said valve skirt, said reciprocable valve element being secured to said arms, and means extending through the head of said cylinder for reciprocating said spider and valve element, said valve elements forming the upper end of the fluid compression chamber,

said reciprocable valve element controlling the passage of fluid into said cylinder and controlling the passage of compressed fluid from said chamber.

4. In a fluid compressor, a cylinder having inlet ports therein, a piston reciprocable in said cylinder, a stationary valve element within said cylinder, and an annular reciprocable valve element, said reciprocable valve element being in leakproot contact with and intermediate said cylinder' and stationary valve element during the compressing movement of said reciprocating piston, said elements cooperating to provide an outlet around said stationary element when the compressing movement of said reciprocating piston is completed.

5. In a fluid compressor, a cylinder having inlet orts therein, a reciprocable compressor p1ston within said cylinder, a stationary valve element within said cylinder, a reciprocable cylindrical valveelement intermediate said stationary valve element and said cylinder, said cylindrical valve element being movable to a position below said stationary element to provide outlet ports for fluid compressed by said piston and to close the inlet ports during 'the compression of the fluid, and an extension on said piston adapted to extend within said cylindrical valve element and adjacent said stationary valve element at the completion of the compression operation to displace substantially the entire volume of fluid therebetwcen.

6. In a fluid compressor, a cylinder having inlet and outlet ports, a. piston reciprocable in said cylinder, a stationary skirted valve element extending within said cylinder, said element having axially extending slots in its skirt portion, a reciprocable stem extending within said cylinder. a support secured to said stem within said cylinder, and an annular valve element secured to the support, said valve element sealing the space intermediate said stationary valve element and said cylinder and controlling the passage of fluid compressed within said cylinder intermediate said piston and valve elements.

7. In a fluid compressor, a cylinder hav ing inlet and outlet ports, a head secured to said cylinder, a piston reciprocable in said cylinder, a hollow valve element. a slotted skirt portionfor the valve element secured to said head, an annular reciprocable valve element intermediate said stationary element and said cylinder and arranged in leak-proof contact therewith, a support having arms extending through the slots in said valve skirt, said reciprocable valve element being secured to said arms, and means extending through the head of said cylinder for reciprocating said support and valve element. said valve elements forming the upper end of the fluid compression chamteasers her, said reciprocable valve element controlling the passage of fluid into said cylinder and controlling the passage of compressed fluid from said chamber.

8. In a fluid compressor, a compression chamber having an inlet port adapted to be closed during the compression operation, a movable member for compressing fluid within said chamber, and a pair of telescopically associated valve elements at the outlet end of said chamber, said valve elements being entirely disposed and within the head portion of the cylinder beyond the cylinder portion swept by the piston. said elements controlling the passage of compressed fluid from said chamber.

9. In a fluid compressor, a cylinder having inlet and outlet ports, a piston reciprocable in the cylinder, a pair of valve elements therefor, one of said elements being stationary and of substantially cylindrical form towards one of its ends and secured at its other end to the head of the cylinder, the valve element being telescoped therefrom within the cylinder. its side walls being spaced from the cylinder walls, the other valve element being annular in form and having outer cylinder wall engaging surfaces and inner surfaces opposing the lateral surfaces of the stationary element, means secured to said annular element to communicate reciprocatory movements thereto from the exterior of the cylinder, said inlet ports being disposed in a lateral side wall of the cylinder so as to be covered by the reciprocatory annular element when moved to its extreme nosition within the cylinder, the inner walls of the annular element adapted to make close fitting engagement with the lateral walls to prevent fluid from passing longitudinally through the annular element when the annular element is in a less ad-,

vanced position within the cylinder, said valve elements havin their opposing faces relatively so relieved from each other in portions thereof that upon movement of the annular element to its extreme position fluid may pass readily between the lateral walls of the stationary element and the inner walls of the valve element to the outlet portion for the cylinder.

10. In a fluid compressor, a combination with a cylinder having inlet and outlet ports and a piston reciprocable in the cylinder, a ,valve mechanism disposed in the head por- Qtion of the cylinder comprising a stationary valve element and an annular valve element telescoped thereover, said annular ele.

through its outlet port when in its opposite admission of fluid through its inlet port extreme position, said annular element in the second said position under the conadapted therebv to permit the discharge of trol of the reciprocable said piston. 19

, fluid from the cylinder between its inner In testimony whereof I hereunto afiix my 5 wall and the outer wall of the stationary signature this 17th day of May, 1924.

element in its first said position, and to V prevent such discharge and to permit the FRANK B. STEARNS. 

